Single-Step Integration of Poly(3-Octylthiophene)\nand Single-Walled Carbon Nanotubes for Highly Reproducible Paper-Based\nIon-Selective Electrodes

Abstract

Calibration of ion-selective electrodes\n(ISEs) is cumbersome, time-consuming,\nand constitutes a significant limitation for the development of single-use\nand wearable disposable sensors. To address this problem, we have\nstudied the effect of ion-selective membrane solvent on ISE reproducibility\nby comparing tetrahydrofuran (THF) (a typical solvent for membrane\npreparation) and cyclohexanone. In addition, a single-step integration\nof semiconducting/transducer polymer poly­(3-octylthiophene) (POT)\nwith single-walled carbon nanotubes (SWCNTs) into the paper-based\nISEs (PBISEs) substrate was introduced. PBISEs for potassium and sodium\nions were developed, and these ISEs present outstanding sensor performance\nand high potential reproducibility, as low as ±1.0 mV (<i>n</i> = 3).